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/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache POI" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache POI", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.poi.poifs.storage;
import java.io.*;
import java.util.*;
import org.apache.poi.poifs.common.PoiFSConstants;
import org.apache.poi.util.IntegerField;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.LittleEndianConsts;
import org.apache.poi.util.LongField;
import org.apache.poi.util.ShortField;
/**
* The block containing the archive header
*
* @author Marc Johnson (mjohnson at apache dot org)
*/
public class HeaderBlockReader
implements HeaderBlockConstants
{
// number of big block allocation table blocks (int)
private IntegerField _bat_count;
// start of the property set block (int index of the property set
// chain's first big block)
private IntegerField _property_start;
// start of the small block allocation table (int index of small
// block allocation table's first big block)
private IntegerField _sbat_start;
// big block index for extension to the big block allocation table
private IntegerField _xbat_start;
private IntegerField _xbat_count;
private byte[] _data;
/**
* create a new HeaderBlockReader from an InputStream
*
* @param stream the source InputStream
*
* @exception IOException on errors or bad data
*/
public HeaderBlockReader(final InputStream stream)
throws IOException
{
_data = new byte[ PoiFSConstants.BIG_BLOCK_SIZE ];
int byte_count = stream.read(_data);
if (byte_count != PoiFSConstants.BIG_BLOCK_SIZE)
{
String type = " byte" + ((byte_count == 1) ? ("")
: ("s"));
throw new IOException("Unable to read entire header; "
+ byte_count + type + " read; expected "
+ PoiFSConstants.BIG_BLOCK_SIZE + " bytes");
}
// verify signature
LongField signature = new LongField(_signature_offset, _data);
if (signature.get() != _signature)
{
throw new IOException("Invalid header signature; read "
+ signature.get() + ", expected "
+ _signature);
}
_bat_count = new IntegerField(_bat_count_offset, _data);
_property_start = new IntegerField(_property_start_offset, _data);
_sbat_start = new IntegerField(_sbat_start_offset, _data);
_xbat_start = new IntegerField(_xbat_start_offset, _data);
_xbat_count = new IntegerField(_xbat_count_offset, _data);
}
/**
* get start of Property Table
*
* @return the index of the first block of the Property Table
*/
public int getPropertyStart()
{
return _property_start.get();
}
/**
* @return start of small block allocation table
*/
public int getSBATStart()
{
return _sbat_start.get();
}
/**
* @return number of BAT blocks
*/
public int getBATCount()
{
return _bat_count.get();
}
/**
* @return BAT array
*/
public int [] getBATArray()
{
int[] result = new int[ _max_bats_in_header ];
int offset = _bat_array_offset;
for (int j = 0; j < _max_bats_in_header; j++)
{
result[ j ] = LittleEndian.getInt(_data, offset);
offset += LittleEndianConsts.INT_SIZE;
}
return result;
}
/**
* @return XBAT count
*/
public int getXBATCount()
{
return _xbat_count.get();
}
/**
* @return XBAT index
*/
public int getXBATIndex()
{
return _xbat_start.get();
}
} // end public class HeaderBlockReader
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